Here's how to determine the number of atoms in CCl₂F₂:

* Count the elements: The molecule has one carbon (C), two chlorine (Cl), and two fluorine (F) atoms.

* Total atoms: 1 + 2 + 2 = 5 atoms

Therefore, there are 5 atoms in a single molecule of CCl₂F₂ (dichlorodifluoromethane).